大白菜异源胞质雄性不育系的核型分析及细胞学鉴定

Cytological Identification and Karyotype Analysis of Alloplasmic Male Sterile Line in Chinese Cabbage

１９９１～１９９３年连续分析了２套大白菜异源胞质雄性不育系ＣＭＳ３４１１－７及ＣＭＳ７３１１不同转育材料的核型，并做了细胞学观察鉴定。发现转育４代和９代具甘蓝型油菜胞质的大白菜胞质雄性不育系，核内染色体数目均为２ｎ＝２０，但２个不育系的核型都程度不同地与相应保持系存在差异，主要表现在随体染色体的大小、位置、数目，近中部着丝点染色体的多寡，染色体的臂比值等方面。说明在回交转育过程中，白菜染色体（ａａ）同油菜染色体（ａａｃｃ）发生了一定的交换或易位。细胞学观察表明，２套不育系花药败育时期均在孢原细胞形成之前，只有极少数花药中的１～３个花粉囊可以发育到四分体或单核花粉期，且大小极不一致，表现特大或特小，说明其不育性比较稳定、彻底。

Alloplasmic male sterile lines, CMS 3411 7 and CMS 7311, which have been applied in hybrids production, were studied in karyotype analysis and cytological identificatian during 1991￣1993. It was found that the chromosome number in F 1BC 4 and F 1BC 9 of Chinese cabbage cytoplasmic sterile line, which sterile cytoplasm was introduced from Brassica napus, Pol CMS and 77A, was 2n=20. There were some differences between CMS lines and their maintainers on size, location and number of satellite chromosomes and the number of submetacentric chromosomes as well as arm ratio of chromosomes. It was indicated that the crossover or translocation was occured between chromosomes of Chinese cabbage ( B.Gampestris, aa) and B.napus (aacc) during back crossing process. Cytological observation indicated that the anthers of two CMS lines were aborted before the sporocyte formation, in only a few anthers, 1￣3 pollen sacs with different size can develop into tetrad or monokaryotic pollen stage. Sterility of these two CMS lines were stable and complete.